We continue our series of article with information that may help patients avoid secondary lymphedema. Our first article described the use of the small needle biopsy as a diagnostic tool, replacing the surgical removal of many lymph nodes.

This page gives information on the Sentinel node biopsy. This newer technique of nodal biopsy focuses on finding the first node that cancer may have spread too.

From studies done, it is estimated that 35 – 40% of cancer patients experience lymphedema as a secondary medical condition. This is due to wholesale removal of lymph nodes. The tragedy too is, that if this is done, and no nodes are found to be malignant, then that person is still seriously at risk for lymphedema.

Intitial stats do look promising with one study indicating that 7% of patients developed lymphedema at the six month follow up time. Long term stats are not yet available either. We will need further 5 year, 10 year and even 20 year follow up studies before we are able to gain an accurate statistic.

So, please be aware of this fact and of the fact that lymphedema prevention steps are still necessary with SNB.

Beware of medical centers claiming a 0% lymphedema ratio for their patients. It grieves me and frankly makes me angry to see this and to me it is totally irresponsible for any center to make such a claim.

Pat

June 4, 2010

Sentinel Lymph Node Biopsy: Questions and Answers

US National Institutes of Health

1. What is a lymph node?
A lymph node is part of the body’s lymphatic system. In the lymphatic system, a network of lymph vessels carries clear fluid called lymph. Lymph vessels lead to lymph nodes, which are small, round organs that trap cancer cells, bacteria, or other harmful substances that may be in the lymph. Groups of lymph nodes are found in the neck, underarms, chest, abdomen, and groin.

2. What is a sentinel lymph node (SLN)?
The sentinel lymph node is the first lymph node to which cancer is likely to spread from the primary tumor. Cancer cells may appear in the sentinel node before spreading to other lymph nodes. In some cases, there can be more than one sentinel lymph node.

3. What is SLN biopsy?
SLN biopsy is a procedure in which the sentinel lymph node is removed and examined under a microscope to determine whether cancer cells are present. SLN biopsy is based on the idea that cancer cells spread (metastasize) in an orderly way from the primary tumor to the sentinel lymph node(s), then to other nearby lymph nodes (1, 2).

A negative SLN biopsy result suggests that cancer has not spread to the lymph nodes. A positive result indicates that cancer is present in the SLN and may be present in other lymph nodes in the same area (regional lymph nodes). This information may help the doctor determine the stage of cancer (extent of the disease within the body) and develop an appropriate treatment plan (2).

4. What happens during the SLN biopsy procedure?
In SLN biopsy, one or a few lymph nodes (the sentinel node or nodes) are removed. To identify the sentinel lymph node(s), the surgeon injects a radioactive substance, blue dye, or both near the tumor. The surgeon then uses a scanner to find the sentinel lymph nodes(s) containing the radioactive substance or looks for the lymph node(s) stained with dye. Once the SLN is located, the surgeon makes a small incision (about ½ inch) in the skin overlying the SLN and removes the lymph node(s).
The sentinel node(s) is/are checked for the presence of cancer cells by a pathologist (a doctor who identifies diseases by studying cells and tissue under a microscope). If cancer is found, the surgeon will usually remove more lymph nodes during the biopsy procedure or during a follow-up surgical procedure. SLN biopsy may be done on an outpatient basis or require a short stay in the hospital.

5. What are the possible benefits of SLN biopsy?
To understand the possible benefits of SLN biopsy, it helps to know about standard lymph node removal. Standard lymph node removal involves surgery to remove most of the lymph nodes in the area of the tumor (regional lymph nodes). For example, breast cancer surgery may include removing most of the axillary lymph nodes, the group of lymph nodes under the arm. This is called axillary lymph node dissection (ALND).

If SLN biopsy is done and the sentinel node does not contain cancer cells, the rest of the regional lymph nodes may not need to be removed. Because fewer lymph nodes are removed, there may be fewer side effects. When multiple regional lymph nodes are removed, the patient may experience side effects such as lymphedema (swelling caused by excess fluid build-up), numbness, a persistent burning sensation, infection, and difficulty moving the affected body area (1, 3).

6. What are the side effects and disadvantages of SLN biopsy?
Side effects of SLN biopsy can include pain or bruising at the biopsy site and the rare possibility of an allergic reaction to the blue dye used to find the sentinel node. Patients may find that their urine is discolored or that their skin has been stained the same color as the dye. These problems are temporary (2).

Although some surgeons consider SLN biopsy to be the standard of care for some cancers, its role and benefit are yet to be determined (2). We do not know whether SLN biopsy improves a patient’s survival or reduces the chance that the cancer will recur (come back). That is why studies are being conducted to compare SLN biopsy with standard lymph node dissection (see Question 8).

7. What research has been done with SLN biopsy?
The concept of mapping (finding) the SLN was first reported in 1977 by a researcher studying cancer of the penis (2, 3, 4). In the 1980s, researchers at the University of California, Los Angeles (UCLA) developed the technique of lymphatic mapping to identify the SLN in patients with melanoma (3). SLN mapping for breast cancer was first reported in 1994 (1, 3). Since then, researchers have improved methods for finding the SLN. Several studies have shown that when the sentinel node is negative, the remaining nodes are usually negative (1, 3). However, these studies were done in a small number of centers and overall survival was not examined.
Other research has focused on the identification of the SLN in patients with cancer of the vulva, cervix, prostate, bladder, thyroid, head and neck, colon, rectum, stomach, as well as non-small-cell lung cancer and Merkel cell cancer (2, 3, 4, 5). Clinical studies continue to examine the accuracy of SLN biopsy and its effect on survival of people with various cancers.

8. What clinical trials (research studies) are being conducted with SLN biopsy?
The National Cancer Institute (NCI) recently sponsored two large randomized clinical trials (research studies) for breast cancer comparing SLN biopsy with conventional axillary lymph node dissection. The trials were conducted by the National Surgical Adjuvant Breast and Bowel Project (NSABP) and the American College of Surgeons Oncology Group (ACOSOG). NSABP and ACOSOG are both NCI-sponsored Clinical Trials Cooperative Groups, which are networks of institutions and physicians across the country who jointly conduct trials. Although several studies have examined the correlation between the sentinel node and the remaining axillary nodes, these are the first two randomized trials that will compare the long-term results of SLN removal with full axillary node dissection. Both of these large trials are now closed.

9. Where can people find more information about clinical trials with SLN biopsy?
The NCI’s Web site provides general information about clinical trials at http://www.cancer.gov/clinicaltrials/ on the Internet. It also links to PDQ®, the NCI’s cancer information database. PDQ contains detailed information about specific ongoing clinical trials in the United States, Europe, and elsewhere.
Information about clinical trials with SLN biopsy is also available from the NCI’s Cancer Information Service (CIS). The CIS, a national information and education network, is a free public service of the NCI, the Nation’s primary agency for cancer research. The toll-free phone number for the CIS is 1–800–4–CANCER (1–800–422–6237). For callers with TTY equipment, the number is 1–800–332–8615. The CIS also offers online assistance through the Help link at CancerGov on the Internet.

Background:
Sentinel lymph node biopsy (SLNB) is less invasive than axillary lymph node dissection (ALND) for staging early breast cancer, and has a lower risk of arm lymphoedema and similar rates of locoregional recurrence up to 8 years. This study estimates the longer-term effectiveness and cost-effectiveness of SLNB.

Methods:
A Markov decision model was developed to estimate the incremental quality-adjusted life years (QALYs) and costs of an SLNB-based staging and management strategy compared with ALND over 20 years' follow-up. The probability and quality-of-life weighting (utility) of outcomes were estimated from published data and population statistics. Costs were estimated from the perspective of the Australian health care system. The model was used to identify key factors affecting treatment decisions.

Results:
The SLNB was more effective and less costly than the ALND over 20 years, with 8 QALYs gained and $883 000 saved per 1000 patients. The SLNB was less effective when: SLNB false negative (FN) rate >13%; 5-year incidence of axillary recurrence after an SLNB FN>19%; risk of an SLNB-positive result >48%; lymphoedema prevalence after ALND <14%; or lymphoedema utility decrement <0.012.

Conclusion:
The long-term advantage of SLNB over ALND was modest and sensitive to variations in key assumptions, indicating a need for reliable information on lymphoedema incidence and disutility following SLNB. In addition to awaiting longer-term trial data, risk models to better identify patients at high risk of axillary metastasis will be valuable to inform decision-making.

PURPOSE:
The purpose of the study was to show that delayed axillary lymph node dissection (ALND) has higher rates of lymphedema compared with immediate ALND, using data from NSABP-B32 at Beaumont Hospital.

CONCLUSIONS:
The rate of lymphedema was higher in delayed ALND but not statistically significant. Comparison, however, is difficult, given the limited sample size. We urge the other centers of NSABP-B32 to validate this, by contacting the node-positive patients for measurements. The lymphedema rate for SLNB alone was 0% and approached statistical significance when compared with node-negative ALND.

Sentinel Lymph Node Biopsy: What Breast Cancer Patients Need to Know

When discussing the surgical treatment of your breast cancer with you, your surgeon will discuss whether or not your breast cancer is invasive. Breast cancers can be confined within the lining of the endothelial cells along the breast duct (in-situ cancers); or it can start to spread beyond the breast duct (invasive cancers). This is important because the blood vessels and lymph vessels that potentially spread the cancer beyond the breast run along this area (See Figure 1). If the cancer has spread beyond the lining of the breast duct, and is picked up by the blood vessels or lymph vessels, then it can potentially spread elsewhere in the body, or “ metastasize.” Lymph vessels are small channels that drain all the tissues of the body. Lymph vessels drain excess fluid back into your circulation. As lymph fluid drains back into your circulation, it goes through lymph nodes. Lymph nodes are collections of lymph tissue that have a high concentration of white blood cells, the cells in your body that fight infection and cancer. The lymph vessels of the breast drain into the lymph nodes in your axilla (underneath your arm), and sometimes into the lymph nodes along your sternum, (or breastbone), and above your clavicle (collarbone) (See Figure 2).

Axillary Lymph Node Dissection:

Traditionally, if your breast cancer is invasive, an axillary lymph node dissection is recommended by your surgeon in order to see if the cancer has spread to the lymph nodes underneath the arm. During an axillary lymph node dissection, the surgeon makes an incision underneath your arm, and removes the bulk of the lymph node tissue that drains from the breast. The lymph node tissue is then sent to the laboratory, and a pathologist looks at the lymph nodes under a microscope and determines if any of them contain cancer. On average, approximately 10 to 15 lymph nodes are removed with this operation. An axillary lymph node dissection usually requires an overnight stay in the hospital. Since the remaining tissues underneath the arm tend to “leak” some lymph fluid when the lymph nodes are removed, a drain is left in place for the first 2-3 weeks after the operation until the area heals. The drain is a flexible plastic tube that exits the skin, and is connected to a plastic collection bulb. When the drainage diminishes to a certain amount, the drain is removed in the clinic. After you go home you are given physical therapy exercises to maintain strength and flexibility in your shoulder while this area heals. Approximately 5-10% of the patients who undergo an axillary lymph node dissection experience chronic problems related to the dissection such as arm swelling (lymphedema), or pain or discomfort in the area of the dissection. Almost all women will have some residual numbness under the inside of the arm.

Sentinel Lymph Node Biopsy:

A sentinel lymph node biopsy is a new technique. This was developed as a test to determine if breast cancer has spread to the lymph ducts or lymph nodes in the axilla without having to do a traditional axillary lymph node dissection. Experience has shown us that the lymph ducts of the breast usually drain to one lymph node first, before draining through the rest of the lymph nodes underneath the arm. That first lymph node is called the sentinel lymph node. That is the lymph node that helps sound the warning that the cancer has spread. Lymph node mapping helps identify that lymph node, and a sentinel lymph node biopsy removes only that lymph node. The sentinel lymph node is identified in one of two ways, either by a weak radioactive dye (technetium-labeled sulfur colloid) that can be measured by a hand held probe, or by a blue dye (isosulfan blue) that stains the lymph tissue a bright blue so it can be seen. Most breast cancer surgeons use a combination of both dyes. This procedure is new. The “best” way to administer the dye, which dye to use, and the benefits and risks of the procedure in various situations is still being studied. A traditional axillary lymph node dissection is the “tried and true” method, and is still considered the “gold standard”.

Advantages:

The advantages to the sentinel lymph node procedure are many. There is no need to stay overnight in the hospital. There is no need for a drain, or physical therapy exercises. Your recuperation from the procedure is faster. You are typically doing your regular activities within a few days, and the incision is well healed within a few weeks. A sentinel lymph node biopsy can lead to a more accurate assessment of whether the cancer has spread to the lymph nodes. In a traditional axillary dissection, the pathologist receives at least 10 lymph nodes or more; there is no way of telling which one is the sentinel lymph node. So the pathologist makes one cut in each lymph node and looks for cancer. When the pathologist receives only one, or a few, lymph nodes from a sentinel lymph node procedure, he or she can make many cuts through that lymph node to look for cancer. A negative sentinel lymph node(s) indicates a >95% chance that the remaining lymph nodes in the axilla are also cancer free. Therefore, there is no need to undergo a full axillary lymph node dissection, or to risk the long term complications and side effects from an axillary dissection.

What to Expect:

If you decide to undergo the procedure, the morning of your operation, you will go see a nuclear medicine specialist who is a physician specifically trained in injecting the radioactive dye used for the procedure. The injections are done into the area of the breast where the tumor is, and/or around the nipple areolar complex of the breast. You will then return to the nuclear medicine department a few hours later, and pictures will be taken which show the pathways the dye takes as it leaves the breast. (See Figure 3) This will help guide your surgeon in identifying the sentinel lymph node. Then you will proceed to the operating room. At the beginning of the operation, your surgeon will inject the blue dye. The surgeon then makes an incision underneath your arm in the area of the axillary lymph tissue. A hand-held sterile probe measures areas that have the radioactive dye. (See Figure 4) The lymph nodes that have taken up the radioactive dye, or are stained with the blue dye, are removed. Usually one to three nodes are removed. These nodes are sent to the pathologist, who then looks at them under a microscope to see if the sentinel node contains cancer. Your incision is closed, and there is no need for a drain. There is no need for physical therapy exercises. Unless you are having another operation done which requires that you stay overnight, you can go home from the hospital that day. The sentinel lymph node biopsy can be done in combination with a lumpectomy, or a mastectomy. The procedure is successful in >90% of those patients whom we think are good candidates for the procedure. If the procedure is unsuccessful in identifying the sentinel node, a full axillary dissection is done.

Axillary Lymph Node Dissection:

Traditionally, if your breast cancer is invasive, an axillary lymph node dissection is recommended by your surgeon in order to see if the cancer has spread to the lymph nodes underneath the arm. During an axillary lymph node dissection, the surgeon makes an incision underneath your arm, and removes the bulk of the lymph node tissue that drains from the breast. The lymph node tissue is then sent to the laboratory, and a pathologist looks at the lymph nodes under a microscope and determines if any of them contain cancer. On average, approximately 10 to 15 lymph nodes are removed with this operation. An axillary lymph node dissection usually requires an overnight stay in the hospital. Since the remaining tissues underneath the arm tend to “leak” some lymph fluid when the lymph nodes are removed, a drain is left in place for the first 2-3 weeks after the operation until the area heals. The drain is a flexible plastic tube that exits the skin, and is connected to a plastic collection bulb. When the drainage diminishes to a certain amount, the drain is removed in the clinic. After you go home you are given physical therapy exercises to maintain strength and flexibility in your shoulder while this area heals. Approximately 5-10% of the patients who undergo an axillary lymph node dissection experience chronic problems related to the dissection such as arm swelling (lymphedema), or pain or discomfort in the area of the dissection. Almost all women will have some residual numbness under the inside of the arm.

Sentinel Lymph Node Biopsy:

A sentinel lymph node biopsy is a new technique. This was developed as a test to determine if breast cancer has spread to the lymph ducts or lymph nodes in the axilla without having to do a traditional axillary lymph node dissection. Experience has shown us that the lymph ducts of the breast usually drain to one lymph node first, before draining through the rest of the lymph nodes underneath the arm. That first lymph node is called the sentinel lymph node. That is the lymph node that helps sound the warning that the cancer has spread. Lymph node mapping helps identify that lymph node, and a sentinel lymph node biopsy removes only that lymph node. The sentinel lymph node is identified in one of two ways, either by a weak radioactive dye (technetium-labeled sulfur colloid) that can be measured by a hand held probe, or by a blue dye (isosulfan blue) that stains the lymph tissue a bright blue so it can be seen. Most breast cancer surgeons use a combination of both dyes. This procedure is new. The “best” way to administer the dye, which dye to use, and the benefits and risks of the procedure in various situations is still being studied. A traditional axillary lymph node dissection is the “tried and true” method, and is still considered the “gold standard”.

Advantages:

The advantages to the sentinel lymph node procedure are many. There is no need to stay overnight in the hospital. There is no need for a drain, or physical therapy exercises. Your recuperation from the procedure is faster. You are typically doing your regular activities within a few days, and the incision is well healed within a few weeks. A sentinel lymph node biopsy can lead to a more accurate assessment of whether the cancer has spread to the lymph nodes. In a traditional axillary dissection, the pathologist receives at least 10 lymph nodes or more; there is no way of telling which one is the sentinel lymph node. So the pathologist makes one cut in each lymph node and looks for cancer. When the pathologist receives only one, or a few, lymph nodes from a sentinel lymph node procedure, he or she can make many cuts through that lymph node to look for cancer. A negative sentinel lymph node(s) indicates a >95% chance that the remaining lymph nodes in the axilla are also cancer free. Therefore, there is no need to undergo a full axillary lymph node dissection, or to risk the long term complications and side effects from an axillary dissection.

Who Shouldn’t Undergo the Procedure:

Unfortunately, the sentinel lymph node biopsy procedure can’t be performed on everyone with an invasive breast cancer. People who have had radiation therapy or surgery in their breast or axilla should not undergo the technique, as changes in the breast and axilla from the radiation therapy or surgery may make the results inaccurate. People who have enlarged lymph nodes underneath their arm, or people who we know already have breast cancer metastatic to their axillary lymph nodes should undergo a traditional axillary lymph node dissection. People who already have had a mastectomy can’t undergo the procedure because there is no accurate way to inject the dye to identify the lymph node. People with large tumors (greater then 5cm) have a higher incidence of lymph node spread of their cancer, and may be better served by a traditional lymph node dissection. They should discuss this with their surgeon. People, in whom it will be difficult to accurately inject the dye, would likely be better served by a full axillary lymph node dissection. This includes those people in whom we are unable to find the primary breast tumor (an “occult” malignancy), and people in whom the tumor is dispersed through more then one area of the breast (a multifocal tumor).

If the Sentinel Lymph Node is Positive:

If the pathology results show that the breast cancer has spread to the sentinel lymph node, then typically you will need to return to the operating room to undergo a complete axillary lymph node dissection. This is done to remove the remaining lymph nodes, which may contain cancer. Since the majority of patients with breast cancer involving lymph nodes receive chemotherapy, the new question for breast cancer specialists has been whether or not it matters if there is cancer in any of the other lymph nodes within the axilla. The answer is that we don’t know yet. There is currently a large national clinical trial called Z0011, which is evaluating exactly that question. In this trial some patients are chosen (randomized) to receive a full axillary lymph node dissection if their sentinel lymph node is positive. Some patients are chosen to not undergo any further lymph node dissection, and they are carefully watched. All of these patients will receive chemotherapy. The two groups of patients will be compared to see if there is a benefit to doing the full axillary dissection if the sentinel lymph node is positive. Or, alternatively, they will be compared to see if there is a detriment to not doing a full axillary dissection if the sentinel lymph node is positive. This is still experimental, and should only be done under controlled circumstances after being enrolled in this trial by a participating breast cancer surgeon. Doing a full axillary lymph node dissection if the sentinel lymph node is positive is still considered “the standard of care” with which all patients should be treated. To do otherwise, risks under treating your breast cancer.

Who Should Do the Procedure:

One of the factors that influences the results obtained with the procedure, is the qualification of the breast surgeon doing the procedure. Initial studies have shown that most surgeons need to do 20-30 sentinel lymph node biopsy procedures before obtaining accurate results using the technique. Surgeons can perform these cases during an accredited residency or fellowship at an institution that does a large number of these cases a year. Alternatively, surgeons attend a conference to learn the technique, then acquire these 20-30 cases as part of a training protocol. During the training period, the surgeon will perform the sentinel lymph node biopsy, and then complete a full axillary lymph node dissection at the same operation. After obtaining the pathology results, the surgeon can then determine if the sentinel lymph node was correctly identified. In addition, the surgeon can determine that the cancer was found in the sentinel node, and not in the lymph nodes that would otherwise have been left behind (false negative rate). After a surgeon has done 20-30 cases in which the sentinel lymph node is identified in >90% of the cases, and the false negative rate is less then 5%, then the surgeon “goes off protocol”, and does sentinel lymph node biopsies without a full axillary dissection. Until the surgeon has completed a large number of cases, and determined her/his accuracy for doing the technique, any cases done “off protocol” may inaccurately determine if there has been spread of cancer to the axillary lymph nodes. It is therefore important, to ask your surgeon if they have done a large number of cases during an accredited residency or fellowship, or if they have completed their learning protocol for the technique. No matter how the training for doing the procedure was acquired, there is some evidence to show that the surgeons who continue to perform this procedure on a regular basis, will have more accurate results from the technique

Summary:

Invasive breast cancer can spread through the lymph ducts and blood vessels to other areas of the body. The sentinel lymph node is the first lymph node that the lymph ducts drain into. Whether or not the cancer has spread to the sentinel lymph node indicates whether the cancer has started to spread beyond the breast. A new technique called sentinel lymph node biopsy identifies this lymph node, and allows only this lymph node to be removed. Removing only the sentinel lymph node can allow breast cancer patients to avoid many of the complications and side effects associated with a traditional axillary lymph node dissection. Patients with invasive breast cancer should discuss sentinel lymph node biopsy with their surgeon.

Center for Dermatooncology, Department of Dermatology, and Central Malignant Melanoma Registry of the German Dermatological Society, Eberhard-Karls-University of Tuebingen, Tuebingen, Germany.

Abstract

BACKGROUND:
This study investigated survival probabilities and prognostic factors in sentinel lymph node biopsy (SLNB) staged patients with cutaneous melanoma (CM) with the aim of defining subgroups of patients who are at higher risk for recurrences and who should be considered for adjuvant clinical trials.

METHODS:
Patients with primary CM who underwent SLNB in the Department of Dermatology, University of Tuebingen, Germany, between 1996 and 2009 were included into this study. Survival probabilities and prognostic factors were evaluated by Kaplan-Meier and multivariate Cox proportional hazard models.

CONCLUSION:
Survival rates of patients with primary CM in stages I-II were shown to be much more favorable than previously reported from non sentinel node staged collectives. For future clinical trials, sample size calculations should be adapted using survival probabilities based on sentinel node staging.

Department of Dermatology, Kyoto University Graduate School of Medicine, Kyoto, Japan.

Abstract

In recent years, sentinel lymph node (SLN) biopsy has been used as a diagnostic and prognostic indicator for a number of tumors, including malignant melanoma. Sentinel lymph node biopsy using combined dye-radiotracer technique improved the detection rate and made the method easier. However, many pitfalls on the SLN procedure have been reported. Herein, we present a new pitfall. A formation of scar and lymph node tissue was detected as a SLN 30 years after lymph node biopsy.

Current status and new applications of sentinel lymph node mapping in non-small cell lung cancer

Sentinel lymph node (SLN) mapping has become a common procedure in the treatment of breast cancer and malignant melanoma. Its primary benefit is that it enables surgeons to avoid nontherapeutic lymph node dissection and the complications that may follow. All present evidence demonstrates the existence of SLNs in non-small cell lung cancer (NSCLC). However, SLN mapping is not widely used in the treatment of NSCLC for several reasons: first, special precautions are required to minimize exposure to radioisotopes; second, it is difficult to detect a dye within anthoracotic thoracic lymph nodes; and third, major complications comparable to the arm edema seen in breast cancer or the lymphedema and nerve injury seen in melanoma are not seen with mediastinal lymph node dissection. However, if the SLN mapping procedure were simplified, it could be used to avoid nontherapeutic mediastinal lymph node dissection in NSCLC. Recently, new applications of SLN mapping have been reported, such as the detection of lymph node micrometastases and segmentectomy for NSCLC. We expect SLN mapping to become a common clinical practice in the treatment of NSCLC in the near future

Sentinel lymph node mapping in gynecologic malignancies

Lymph node status is the most important prognostic factor for women with vulvar, cervical and endometrial carcinoma and complete lymph node dissection has historically been an integral part of the surgical treatment of these diseases. Lymphadenectomy can be morbid for patients, who may experience wound breakdown, lymphocyst formation or chronic lymphedema, among other problems. Sentinel lymph node mapping is a newer technology that allows selective removal of the first node draining a tumor thereby allowing a potentially less aggressive procedure to be performed. Sentinel node mapping is well accepted for the management of breast carcinoma and cutaneous melanoma, and has resulted in reduced morbidity without adversely affecting survival. Sentinel node mapping is currently being investigated for treatment of gynecologic cancers. Recent studies show promise for incorporating the sentinel node mapping technique for treatment of several gynecologic malignancies.

OBJECTIVES: Sentinel lymph node (SLN) dissections have a high sensitivity and negative predictive value for the detection of metastatic disease. The objective of this study was to examine the inguinal recurrence rate along with complication rates for patients undergoing inguinal SLN dissection alone for vulvar carcinoma.

METHODS: An IRB approved prospective study enrolled patients with biopsy proven squamous cell carcinoma of the vulva. Peritumoral injection of Tc-99 sulfur colloid and methylene blue dye was used to identify SLNs intraoperatively. Patients with SLNs negative for metastatic disease were followed clinically. Patients with metastasis detected in a SLN subsequently underwent a full groin node dissection followed by standard treatment protocols.

RESULTS: Thirty-six patients were enrolled onto study with 35 undergoing a SLN dissection. All SNL dissections were successful with a mean of 2 SLN obtained per groin. There were 24 patients with stage I disease, 8 stage II, 3 stage III and 1 stage IV. A total of 56 SLN dissections were performed with 4 patients found to have inguinal metastasis by SLN dissection. There were 31 patients with a total of 46 SLN dissections found to be negative for metastatic disease. The median follow-up has been 29 months (range 8 to 51) with 2 groin recurrences for a groin recurrence rate of 4.3% and a recurrence rate per patient of 6.4%. There have been no reports of groin breakdown, extremity cellulitis or lymphedema.

CONCLUSIONS: The recurrence rate for patients undergoing inguinal sentinel node dissection alone is low. These patients did not experience any complications as seen with complete groin node dissections. Sentinel lymph node dissection should be considered as an option for evaluation of inguinal nodes for metastatic disease.

The False-Negative Rate of Sentinel Node Biopsy in Patients with Breast Cancer: A Meta-Analysis.

May 2012

Pesek S, Ashikaga T, Krag LE, Krag D.

Source

University of Vermont College of Medicine, Burlington, VT, 05405, USA.

Abstract

BACKGROUND:
In sentinel node surgery for breast cancer, procedural accuracy is assessed by calculating the false-negative rate. It is important to measure this since there are potential adverse outcomes from missing node metastases. We performed a meta-analysis of published data to assess which method has achieved the lowest false-negative rate.

METHODS:
We found 3,588 articles concerning sentinel nodes and breast cancer published from 1993 through mid-2011; 183 articles met our inclusion criteria. The studies described in these 183 articles included a total of 9,306 patients. We grouped the studies by injection material and injection location. The false-negative rates were analyzed according to these groupings and also by the year in which the articles were published.

RESULTS:
There was significant variation related to injection material. The use of blue dye alone was associated with the highest false-negative rate. Inclusion of a radioactive tracer along with blue dye resulted in a significantly lower false-negative rate. Although there were variations in the false-negative rate according to injection location, none were significant.

CONCLUSIONS:
The use of blue dye should be accompanied by a radioactive tracer to achieve a significantly lower false-negative rate. Location of injection did not have a significant impact on the false-negative rate. Given the limitations of acquiring appropriate data, the false-negative rate should not be used as a metric for training or quality control.